It doesn't matter what side of the debate you're on when it comes to using 3D printers to make guns, how could anyone being against using the technology to build a machine gun that folds and fires an endless barrage of paper airplanes?
There are a few off-the-shelf parts in Dieter Michael Krone's wonderful creation, including the guts from a cheap cordless screwdriver to power it. But everything else was created with the help of a 3D printer, and certainly a brilliant grasp of engineering.
It's not something you could easily sneak into the back of a classroom, but if you can get this thing to the top of a skyscraper you can certainly have a bit of fun watching a barrage of paper planes drift down into a city. [Dieter Michael Krone via Tastefully Offensive]